Question
Chemistry Question on Alcohols, Phenols and Ethers
Which named reaction contains dichlorocarbene intermediate?
A
Aldol condensation
B
Cannizaro
C
Kolbe’s reaction
D
Riemen-Tiemann reaction
Answer
Riemen-Tiemann reaction
Explanation
Solution
When phenol is refluxed with the chloroform in the presence of an aqueous solution of sodium hydroxide at340K340Kfollowed by the hydrolysis, the aldehydic group(-CH=O)(-CH=O)gets introduced in the ring at the ortho position to the phenolic group.
Reimer Tiemann reaction which converts phenol to ortho-hydroxybenzaldehyde involves the formation of dichlorocarbene which acts as an electrophile and attacks on the ortho position of phenol.